Modern telecommunications systems comprise a plurality of interconnected telecommunications networks, among others a wired or fixed telecommunications network, such as the Public Switched Telecommunications Network (PSTN) or the Integrated Services Digital Network (ISDN), and wireless cellular radio or mobile telecommunications networks, such as operating in accordance with the Global System for Mobile communications (GSM) or the Universal Mobile Telecommunications System (UMTS) standard.
At the moment the telecommunications network can be built based on two main technologies, which are circuit-switched and packet-switched. In a circuit-switched network a physical path is obtained for and dedicated to a single connection between a calling party and the called party for the duration of the connection. In a packet-switched network relatively small units of data called packets are routed through a network based on the destination address contained within each packet. Breaking communication down into packets allows the same data path to be shared among many users in the network. (Most traffic over the Internet uses packet switching and the Internet is basically a connectionless network).
The phenomenal growth in popularity of the Internet has resulted in a tremendous interest in using packet-switched network infrastructures (e. g., those based on IP addressing) as a replacement for the existing circuit-switched network infrastructures used in today's telephony. From the network operators' perspective, the inherent traffic aggregation in packet-switched infrastructures allows for a reduction in the cost of transmission and the infrastructure cost per end-user.
However, discarding all investment made in circuit-switched networks and changing over to an all packet-switched network is not a sound proposition from an economical point of view. Coupled with the huge investments to obtain a worldwide all packet-switched network that is able to support voice, data, video, etc. it is a sounder proposition to establish an evolution path from circuit-switched networks towards a viable all-IP network. The evolution toward all-IP begins with the simultaneous/parallel use of the circuit-switched and packet-switched network to deliver combinational/multimedia services.
The simultaneous use of the circuit-switched network and packet-switched network for initiating a connection between calling and called party can result in an alerting signal on both networks. The present technology requires that both the circuit-switched and packet-switched network independently process the alerting signal resulting in a slower handling of said alerting signal, in a less efficient use of the telecommunications network and more errors (user forgets to respond to one of the alerting).
At this moment no provisions are known or implemented in the present telecommunications system allowing for a fast, efficient and error proof response from the called party and where the packet-switched network and circuit-switched network cooperate to process the alerting of the enhanced connection.